Sharp Transition Multiband Filter in Speech Processing Scheme for Hearing Impaired
Joseph X. Rodrigues, Lucy J. Gudino and K. R. Pai
DOI : 10.3844/ajeassp.2012.42.48
American Journal of Engineering and Applied Sciences
Volume 5, Issue 1
Problem statement: A simple analytical approach to the synthesis of a sharp transition, linear phase, multiband FIR filter is presented. The filter magnitude response is modeled using trigonometric functions of frequency. Approach: Employing variable density of ripple cycles in passband and stopband regions with large density of ripples cycles at the sharp transition edges, reduces the abrupt discontinuities at these edges. Results: As a result, Gibb’s phenomenon is reduced in the filter implementation thus giving a flat passband and good stopband attenuation. A closed form expression for impulse response coefficients is obtained. The filter design is easily tunable and allows for variation in transition bandwidth of each band. A speech processing scheme is implemented using a pair of the proposed sharp transition multiband FIR filters to split the speech spectrum into complementary short time spectral bands. Conclusion: The adjacent speech formants are fed dichotically to the two ears to reduce the effect of spectral masking and hence improve speech perception in sensorineural hearing impaired.
© 2012 Joseph X. Rodrigues, Lucy J. Gudino and K. R. Pai. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.